In his 2005 book Christianity and the Crisis of Cultures, then-Cardinal Joseph Ratzinger asks: “Is faith truly an attitude worthy of a modern adult?”

This question is not new. It has been around at least since the beginning of the “modern” period — since the 17th century. It was then that French mathematician and philosopher Blaise Pascal crafted what is still known as “Pascal’s Wager.” His purpose was to provide a reasonable foundation for belief in the God of Christianity.

In his book, the future Pope Benedict XVI addresses the same theme. He calls into question agnosticism, the claim that it cannot be known if God exists, a position akin to atheism, the outright claim that God does not exist.

Not knowing what to believe, the agnostic lives a life of unbelief. “If you don’t know that God exists, then you end up living as an unbeliever,” Benedict writes.

Pascal was a pioneer in what would be known much later as “decision theory.” He applies his expertise here in an attempt to persuade unbelievers to decide for God (and Christianity).

In a nutshell, the wager is: If God exists (and Christianity is true) and you choose not to believe, then you lose everything. But, if God exists (and Christianity is true) and you choose to believe, then you gain everything.

We must make a distinction here between belief in God and belief in Christianity. The Church holds that belief in God can be arrived at through reason. But belief in Christianity requires Revelation. Neither Pascal nor the Pope is trying to use reason to prove the truthfulness of Christianity, but to show that belief in the God of Christianity is reasonable.

There is more to consider in Pascal’s Wager than reason, reasonableness and Revelation. Given the obvious, what is preventing unbelievers from making the right choice?

Benedict believes that the bad example of many Christians, who claim to believe in God but live as if he did not exist, contributes to the spread of unbelief. Indeed, he thinks the greatest need in the world today is the good witness of Christians who will make God more credible to the world.

Another related reason for the spread of unbelief is expressed by St. Paul, in speaking of the skepticism of his pagan contemporaries:

“What can be known about God is plain to them. Ever since the creation of the world his invisible nature, namely his eternal power and deity, has been clearly perceived in the things that have been made” (Romans 1:19-20). But “by their wickedness they suppress the truth” (Romans 1:18).

Pascal echoes St. Paul when he explains why some persist in their unbelief. He says that since the rational choice is not being made, there must be some irrational obstacles. He calls them “noxious” pleasures. Therefore, according to St. Paul and Pascal, the basis for unbelief is not grounded in reason, but in immorality. Many unbelievers are not truly concerned with the reasonableness of belief; they simply do not want to give up their sinfulness, which is the real “reason” they reject God and Christianity.

The demands of the real Truth are too great for them.

St. Augustine’s life provides a good example of this. Raised by a Christian mother, he nevertheless decided to postpone baptism. For years he struggled with error and sexual immorality. He took a mistress at an early age and spent years as a Manichean, a form of heresy.

He is famous for the saying “O Lord, help me to be pure, but not yet.” This epitomizes the place of immorality as an obstacle for many people to belief in (and practice of) Christianity.

Augustine’s struggle with immorality prevented him from belief in the God of Christianity. Finally, after years of intercessory prayer by his mother, and under the tutelage of St. Ambrose, he gave up his mistress and received the Catholic faith.

However, not everyone has a St. Monica praying for them for decades and the gift of someone like St. Ambrose to guide them.

What, then, about today’s unbelievers?

As the Pope has written, bad example by Christians is a major force in the spread of unbelief. But what is bad example except the immorality of one who claims to believe?

The other side of the coin, as we read from Pascal and St. Paul, is the obstacle presented by the immorality of the unbeliever. All those who live as if there is no God, whether it be the Christian of bad example or the unbeliever, have this one thing in common: immorality. Therefore, we can equate, directly and indirectly, unbelief with immorality.

The Pope concludes with the advice Pascal gave to his nonbelieving friends: Try to live as if God exists because the unbeliever who acts as if God exists becomes more morally responsible. Through the experience of living this way, one will realize the truthfulness of his choice: “This is the wager, and the winnings are salvation.”

We can see now that a New Evangelization has to set out from fewer rational arguments and more encouragement of moral goodness. That’s how “irrational” obstacles can be cleared away.

John the Baptist’s “Repent!” preceded Christ and his message. Jesus did not say, “Believe the good news and repent!” He said, “Repent and believe the good news!”